Antimicrobial and Anti-inflammatory Cyclic Tetrapeptides from the Co-cultures of Two Marine-Derived Fungi

• Published in: Journal of natural products (Washington, D.C.) Vol. 87; no. 2; pp. 365 - 370
• Main Authors: Li, Qin, Li, Shasha, Li, Shunwang, Hao, Xiaomeng, Wang, Anqi, Si, Shuyi, Xu, Yanni, Shu, Jicheng, Gan, Maoluo
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society and American Society of Pharmacognosy 23.02.2024; Amer Chemical Soc
• Subjects: Alternaria; Anti-Infective Agents; Anti-Inflammatory Agents - pharmacology; Aspergillus; Chemistry, Medicinal; coculture; Coculture Techniques; Edwardsiella tarda; Fungi; interleukin-6; Life Sciences & Biomedicine; Magnetic Resonance Spectroscopy; Molecular Structure; Peptides, Cyclic - chemistry; Peptides, Cyclic - pharmacology; Pharmacology & Pharmacy; Plant Sciences; Science & Technology; spectral analysis; Tandem Mass Spectrometry; ABSOLUTE-CONFIGURATION; NATURAL-PRODUCTS; DISCOVERY; ASPERGILLUS
• ISSN: 0163-3864; 1520-6025; 1520-6025
• DOI: 10.1021/acs.jnatprod.3c01115

Violaceotides B–E (1–4), four new cyclic tetrapeptides, along with seven known compounds, were identified from the sponge-associated Aspergillus insulicola IMB18-072 co-cultivated with the marine-derived Alternaria angustiovoidea IMB20-805. Their structures were elucidated by extensive analysis of spectroscopic data, including HRESIMS, 1D and 2D NMR, and MS/MS data. The absolute configurations were determined by the advanced Marfey’s method. Compounds 2, 3, and violaceotide A (5) displayed selective antimicrobial activities against the aquatic pathogenic bacteria Edwardsiella tarda and E. ictaluri. In addition, compounds 1–5 showed inhibitory activities against the LPS-induced expression of the inflammatory mediator IL-6 in RAW264.7 cells at a concentration of 10 μM.